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authorMarc Zyngier <[email protected]>2024-03-21 11:54:14 +0000
committerOliver Upton <[email protected]>2024-04-01 01:33:29 -0700
commitb3320142f3db9b3f2a23460abd3e22292e1530a5 (patch)
tree49a808439e6b70ca97493a2c8e9a2bae037c3afc /tools/perf/scripts/python/event_analyzing_sample.py
parent4c36a156738887c1edd78589fe192d757989bcde (diff)
arm64: Fix early handling of FEAT_E2H0 not being implemented
Commit 3944382fa6f2 introduced checks for the FEAT_E2H0 not being implemented. However, the check is absolutely wrong and makes a point it testing a bit that is guaranteed to be zero. On top of that, the detection happens way too late, after the init_el2_state has done its job. This went undetected because the HW this was tested on has E2H being RAO/WI, and not RES1. However, the bug shows up when run as a nested guest, where HCR_EL2.E2H is not necessarily set to 1. As a result, booting the kernel in hVHE mode fails with timer accesses being cought in a trap loop (which was fun to debug). Fix the check for ID_AA64MMFR4_EL1.E2H0, and set the HCR_EL2.E2H bit early so that it can be checked by the rest of the init sequence. With this, hVHE works again in a NV environment that doesn't have FEAT_E2H0. Fixes: 3944382fa6f2 ("arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative") Signed-off-by: Marc Zyngier <[email protected]> Acked-by: Catalin Marinas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Oliver Upton <[email protected]>
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